This invention relates to a vibrating mold assembly and a method of operation, which mold assembly has a cooling jacket disposed around a mold tube for the continuous casting of metal billets. More particularly, the length for a mold assembly can be varied from one dimension to another by employing different lengths molds in combination with attaching or detaching extensions to the mold assembly especially the cooling jacket, and replacing the inner wall of the cooling jacket and the mold.
Present day continuous casting, vibrating mold assemblies for casting metals, such as ferrous metals, are conventionally of a fixed length. This fixed length for the mold assembly is usually selected based on the solidification rate of metal with a low carbon content. This fixed length is such that it insures that sufficient wall portions of the casting freeze are thick enough so that the casting skin does not break thereby allowing the molten metal from the core to pour out of the casting.
If metals with carbon levels, particularly in a medium range particularly between 0.15 and 0.35 and higher are being cast using the open stream-mold oil practice, the molten metal solidifies unevenly. The metal shrinks away from the mold unevenly and faster than the low carbon metals thereby causing the solidification to become uneven resulting in an unacceptable product shape. The longer the casting mold, the longer the metal shell is in the mold. This added time makes the already uneven solidified shell worse because of the cooling influence of the water cooled copper tube.
The mold tubes of present day fixed length mold assemblies similar to those mentioned above for casting steel metals are usually made of copper. These copper mold tubes have a tendency to quickly wear in the lower section which then have to be discarded, resulting in high replacement costs for the mold tube.
These aforesaid limitations of a fixed length mold assembly for casting both relatively low and high carbon steels is further explained in U.S. Pat. No. 3,528,487. There is therefore a need in the industry to be able to adapt a mold assembly to a length which would permit sufficient mold time proportional to the solidification rate and carbon range of the different carbon content metals. There is a further need in the art to provide a copper mold tube which can be salvaged when a section of the tube wears.